One apparatus and method of setting a bead ring against the plies of a tire carcass is shown in U.S. Pat. No. 3,871,942 to V. E. Henley et al., assigned to the assignee of the present invention. The bead setting apparatus of that patent, shown in FIG. 7 and described in column 6, lines 49 to 66, has a thin cylindrical flange on which the bead ring is supported before it is pushed against the carcass plies on the drum shoulder by a radially extending plate located behind the bead ring. Since the supporting cylindrical flange extends only part way within the inside edge surface of the bead ring, this flange does not touch the carcass plies or the drum shoulder, or otherwise interfere with the bead setting apparatus as it drives the bead ring against the carcass plies.
However, in order to obtain a tight wrapping of the carcass plies around the building drum shoulder during the expansion of the drum and the subsequent setting of the bead ring, it has been found desireable to lengthen the cylindrical flange of the bead setting apparatus. With such a longer flange, extending fully across the inside surface of the bead ring and protruding toward the shoulder of the building drum, the bead setting apparatus is moved in close to the drum during its expansion. With the apparatus so positioned, the carcass plies will be forced laterally around the drum facing edge of the long flange as they are pulled radially outwardly by the expanding drum. These plies will thus be wrapped more tightly against the shoudler of the drum and will conform more to the contour of the shoulder, thus insuring better cord length control.
While a long bead carrying flange helps in wrapping the carcass plies around the drum shoulder, it makes the actual setting of the bead ring more difficult. In the past, an inflatable push-off bladder has been used to push the bead ring off its long flange and against the carcass plies on the shoulder of the building drum. Such a bladder, however, cannot provide the required force to push the bead ring off the long cylindrical flange when the bead ring fits snugly over the flange. On the other hand, when the bead ring fits loosely on the flange, it is likely to become canted and positioned off center when it is seated against the carcass plies on the building drum. The push-off bladder itself can also contribute to the improper and insecure positioning of the bead ring, because it does not present a solid back-up surface for the bead ring and does not push hard enough on the bead ring, especially during the final stages of the bead setting.